Why does he only talk to me when we are alone?

My boyfriend & I talk to each other a lot. And we were friends first before we started dating he has always talked to me when we are alone. He says he "likes talking to me alone."

I mean we talk in public so people see us talking together but we just don't have other people like right beside us when we talk. We haven't ever talked in a group before.

I don't know why, but we just haven't. I personally like it when we talk alone I mean I have nothing to complain about. It gives us more privacy & sometimes people can pressure you to do things when you are a couple.

Is this a bad thing? And why does he like talking to me when we are alone? Is it for the same reason I do?